Wet grinding knife sharpener



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WET GRINDING KNIFE SHARPENER Filed July 16, 19417 H il l l IHWQ lIHIIIIIH 2 Sheets-Shet 2 INVENTOR,

EMMA! W mm BY Hi5 ATTUEMEYE Patented Jan. 31, 1956 TITED STATES rarenrOFFICE WET GRINDING KNIFE SHARPENER Pennsylvania.

Application .luly 16, 1947-, Serial No. 751,225

11 Claims. 1

This invention relates to a wet grinding knife sharpener, and moreparticularl pertains to such a sharpener wherein the operator draws theedge of the knife back and forth across a side face of. a grinding wheelmounted for rotation on a horizontal axis, the knife being held at. aconstant sharpening angle .to either face by an. associated conicalguide mounted coaxially with the grinding wheel, and wherein the drawingmovement of the. knife rotates the grinding Wheel.

The conical knife guides, one for each face of the wheel, areresiliently held. against the respective sides of the grinding wheel bysprings, and their small ends enter recesses in the sides of thegrinding wheel, said recesses being coaxial with the axis of rotation ofthe wheel. The spring action makes the device self-adjusting.

The lower portions of the grinding wheel and knife guides are submerged.in a fluid which, as they rotate, washes away the. cutting debris.

The knife guides also act to dress the faces of the grinding wheeladjacent the recesses, in a. manner to be described, so that the groundedge of the knife will never be dulled by use on a mutilated grindingwheel. Each conical knife guide, moreover, has a circle of holes,concentric with. the axis of rotation of the assembly of grind wheel andconical knife guides, and, as the said assembly is rotated in the fluid,during the sharpening process, the cuttings from the knife blade and thedebris from the grinding wheel are Washed away, to the end that asuperior wet grinding condition is obtained.

In order that both sides of the cutting edge of a knife blade may beground without turning the knife sharpener end for end, I provide theconical guide member on each face of the grinding wheel, so that firstone guide may be used for grinding one side of. the cutting. edge, andthen the other guide may be used for grinding the other sideof thcutting edge.

Therefore, it is the principal object of my invention. to provide aknife-actuated grinding wheel which has a container for holding fluidfor washing the grinding Wheel while it is being used.

Another object of the invention is to provide a knife-actuated grindinwheel provided with knife guides which also function to dress the wheelwhile it is being used, said guides being spring urged against thegrinding wheel and, thus, self-adjusting.

Another object of the invention is to provide a knife-actuated grindingwheel, with guides 2 whichv keep the blade to be sharpened at thecorrect. angle. and which protect the cutting edge from edge contactwith. any portion of the grinding wheel.

With these and further objects in. view, which will become apparent.from the description to follow, the invention will be described withreference. to the. drawings in. which;

Fig. 1 is a perspective view of. my novel. knife sharpener.

Fig. 2 is an. end elevation of the knife sharpener.

Fig. 3 isa top plan. view of the knife sharpener.

Fig. 4 is a. side elevation of my knife sharp.- ener,. with parts being.broken away to show one of. the knife'guides and the. spring cooperatingtherewith.

Fig. 5 is an end elevation of the knife sharp} ener, partly in sectionapproximatel on the line 55 of Fig. 1, to. show the. mounting of thegrinding, wheel. and the relationship. of the knife guides. with.respect thereto..

Fig. 6 is an. elevation of one of the. knife guides as it appears from.that side. which makes. con.- tact. with the grind. stone.

Fig- 7 is a sectional View of the knife guide of Fig. 6. in a planeincluding the axis of rotation.

Fig. 8 is an enlarged detail section of part of the grinding wheel. andone of the knife guides, showing the position of the. parts with a knifein position for sharpening. V

Fig. 9 is an. elevation of one of the springs.

In the drawings, the same reference numerals are. applied to the sameparts throughout the several views, and the sectional views are taken onthe: section lines looking. in the direction of the arrows...

Referring to Fig. 1, I provide a support casing 20 having feet- 2| and-22, a. fluid cup 23:, and having. upwardly projecting side members 214and 25. The side members. 24 and 25 preferably, but not necessarily,have a circular upper edge of a radius equal to. the radius of thegrinding wheel to be used, as will be described. Concentric with thecenter of curvature of side members 24 and 25 are apertured hearingbosses 2B and 21 (see Fig. 2) having a shaft 28' aflixed therein, acrossthe cup 23,. at brim leveL. which acts as a. mount.- in for sleeve 25(Fig. 5) on which the. grinding wheel and knife. guides, to bedescribed, are mounted. for rotation. The shaft 28 is fitted tightlyin.the bearing apertures. as itis; desirable to have the cup leakproof' atthose points to prevent the escape of. fluid. It will b appreciated 3that the shaft 28 can be mounted rotatably if desired. Sleeve 29 extendssubstantially the length of that portion of shaft 28 which is within theinside of the cup and is rotatable upon shaft 28. Sleeve supports thegrinding wheel, knife guides, and knife guide springs.

I provide an abrasive grinding wheel 30, preferably of stone or mineralsubstance, having side faces 3! and 32 which are substantially paralleland lie in planes normal to the axis of rotation of sleeve 29. Grindingwheel 35 has a central circular aperture 33, with an insidecircumferential groove 34 (Fig. 8) located on a plane parallel to andhalfway between faces 3| and 32. On sleeve 29 is mounted a narrowsupport wheel 35 having a rim portion 3'6 which has therein acircumferential groove 31. The grinding wheel is held on said wheel bymeans of a circular wire member 38 which, by springing outwardly, keystogether said grinding wheel and said support wheel. From what has beensaid, it will be apparent that the grinding wheel 35 is rotatable withreference to the shaft 28. It will be understood from what follows thatthe mounting of the grinding wheel is not of controlling importance solong as there is a central recess in each of the grinding wheel faceswhich will allow entry therein of the small end of the associatedconical knife guide, to be next described. 7

Referring to Figs. 2 and 5, rotatably mounted on sleeve 25 is a leftknife guide 40 and right knife guide 4i, each of which is roughlyconical in shape, with the small end truncated so as to fit over thesleeve 29 and to fit into the aperture 33 (Fig. 8) for a slightdistance. The right-hand knife guide 4! will be particularly describedas typical of both knife guides, guide 46 being a left-hand counterpartof guide 4!. The circumferential rim 42 is bent parallel to the axis ofrotation, and is at a distance from the axis of rotation equal to thatof the periphery of the grind stone 30, so the two are at the samelevel, as best seen in Fig. 2, in which position they prevent theaccidental entry of a knife blade into the wrong place. The crosssection of said knife guide 4!, as shown in Fig. 8, further shows,inwardly of rim 42, a vertical band 43 which is bent to angular portion44 which has an inward offset 45 a further angular portion 46, and thena vertical section 4?, which has therein an aperture 48 which isslightly larger in diameter thanthe diameter of sleeve 29 so that theknife guide in addition to being rotatable upon sleeve 29 may wobble,slightly, thereon. At 49 Where the knife guide makes contact with theedge 50 of the grinding wheel aperture 33 there is provided a circle ofholes 5! (see Fig. 6) which aid in the carrying away of cutting debris.

It will be understood that the knife guides, as represented by guide 4!,are not true truncated cones, but are modified to provide the bearingportion 47 and to provide the band 52 so that a knife blade 53 laidagainst the guide touches only at shoulders 54 and 55. The face 56 ofthe knife blade not being in contact with the knife guide receives nofrictional rubbing action thereby as the knife blade is drawn back andforth by the operator. Therefore, the depressed band 52 eliminates themarring of the sides of the knife sharpened thereon, points 54 andproviding adequate support and guidance for the knife. Moreover, a twopoint contact with the knife face provides a more stable knife restingposition, at the proper angle for sharpening, than would occur in usinga perfectly fiat support surface.

The conical slope of the knife guide determines the included angle ofthe cutting edge to be ground on the knife and may be sloped as desired.

As seen in Fig. 8, sleeve 29 has on the end thereof a groove 66 forsupporting a helical-spiral spring 5i (see also Fig. 9), the small endof which engages groove 5%] and the large end of which abuts against theguide 4! to resiliently hold it against the edge 5i: of the grindingwheel.

As a knife blade 53 is drawn back and forth, after it has been restedagainst the guide, the grinding wheel and guide will rotate about shaft28. As the knife blade 53 is forced downwardly into the V-shaped anglebetween the knife guide and the stone, the knife guide on the upper sideis forced outwardly which wobbles the whole knife guide on its mountingsleeve 29 so that the lower part thereon receives the full pressure ofthe spring forcing it against the part of the edge of the grinding wheelaperture 33 which is in the lowermost position, and breaks off any rimleft on face 32 of the grinding wheel, at the edge of aperture 33, whichmay be made by wearing away of the portion of the stone just outwardlyfrom it due to the abrasion of the knife. As the grinding wheel turnsthis dressing action progresses entirely around edge 50. In this way,the face 32, of the stone is kept in a dressed condition so that thecutting edge of the knife blade sharpened thereon will not be dulled bythe existence of a rim caused by wear of the grindstone. it will beunderstood that there may be some slight rotational movement of knifeguide 4| with respect to the grinding wheel, as they are not coupledtogether, and this in conjunction with the holes 5!, in the knife guide,further helps in the dressing action.

Due to the fact that the knife guide is resiliently held against thegrinding wheel the knife blade can never jam in the sharpener.

As seen in Fig. l, fluid Ill, preferably water, is placed in the cup toa water line H which may be marked on the outside of the casing, and themovement of the grinding wheel and the knife guides, rotationally, swishthe water in and out through the holes, carrying away the cuttings fromthe knife and the debris from the stone, thus keeping such harmfulmatter away from the grinding area, and accomplishing a wet grindingaction. The cup in the casing collects and keeps off the surface onwhich the grinding device is used, all the cutting debris, which may belater dumped therefrom.

As seen in Fig. 2, the knife guide 40 is a lefthand duplicate of knifeguide 4! and is mounted and acts in the same manner.

In operation, the operator grinds one edge face of the knife using theright knife guide and grinds the other edge face of the knife by usingthe left knife guide, both sides of the stone being used in such acomplete operation. Although use of both sides of the grinding wheel ispreferable from a convenience standpoint, the action of grinding bothfaces of the cutting edge can be obtained by the use of one side of thegrinding wheel if the same is turned end for end after grinding one edgeface so that the knife is en.- tered from the other side.

A few back and forth movements of the knife are suiiicient to sharpenthe knife to a very keen cutting edge, and the parts are so positionedthat the point of a knife can be sharpened as easily as, the middleportion of the edge, due: to. the fact that. the; knife. guides; areresiliently in con tact. with the stone. and are. notstationar-y withrespect thereto;

The various portions ofthe device such as the casing, the sleeve, andthe knife guides may be made of any type of metal, preferablynon-corrosive and not hardened to a point where they would damage theknife accidentally drawn thereon, and the grinding wheel may be made ofany suitable abrasive material, natural or of compacted and cementedparticles, or the grinding wheel may be of hard material which has anabrading surface in the form of file or other type of roughened surface.

The fluids to be used with the knife sharpener are a matter ofconvenience, and water has been specified as the most convenient fluid,although non-evaporating fluids and lubricant fluid such asoil may beused if such is desired.

I am aware that certain details of construction specified are notnecessary to the successful operation of my invention and I' do not deemmyself limited to the particular construction used, therefore, F claimmy invention broadly.

What I claim is:

1. In a knife sharpener. in combination, a casing having spaced sidemembers; a shaft held'by and extendingbetweensaid side members; anabrasive wheel mounted on said shaft for rotation between the sidemembers, said wheel having a circular recess. coaxial with said shaft; aknife guide having" a small endportion and a rim portion, rotatably-rnounted on said shaft; the small end having a hole therein of adiameter large enough through which said shaft protrudes, so that saidguide may be wobbled on said shaft the small endentering said recess sothe side of the guide rests against the peripheral edge of the recess-,said guide havin a circumferential circle of holes extending therearoundat its points of contact with the wheel foraiding in removing cuttingdebris, and means resilientlyv holding such guide against the associatedrecess in t e wheel.

2. In a knife sharpener, in combination, a fluid holding cup; a wheelabrasive member mounted on a shaft held bythe cup, forrota tionalmovement, said shaft-being horizontal and the. lower portion of; thewheel belowthe shaft being within the confines of the cup and the upperportion of' the Wheel above the shaft being above the upperedges of' thecup; truncated conical knife guide means held against the. side of thewheel, the. truncated end pointed toward the wheel and slipped over theshaft until the frwsto-conical surface comes in contact with said wheel,the frusto-conical face acting as a knife positioning means, so that aknife having the side of its blade laid thereagainst has the oppositecutting edge face positioned at the proper angular position on thewheel, and so that drawing the knife back and forth grinds said edge incontact with the wheel; audafi uid heldin the, cup in which fluid, thewheel and the ide: m ans. s. a h s. of. cu n d bri upon rotation of saidstone andguide: means by the sharpening operation.

3. In a knife sharpener as set forth in claim 2, in which acircumferential row of holes are formed in the truncated end of theknife guide means adjacent to the line of contact with the abrasivewheel for aiding in removing cutting debris.

4.... In. a knife sharpener as set forth. in claim. 2,. in; which thefrustoeconical surfaces of the knife guidemeans. is provided with anannular recess to form spaced-apart, knife supporting points.

5. In av k-nife sharpener as set forth in claim 2, including means; forresiliently holding the knife guide means; against the abrasive wheel.

Ina. knife sharpener, in combination, an abrasive wheel having acircular aperture extending from side to side and, being coaxial. withthe. Wheel axis; a narrow disc mounted within the aperture on a planehalfway between the planes. of." the side faces of the wheelfsaid dischaving a central aperture, and said disc having its periphery in contactwith the wheel and fastened thereto; a sleeve on which the disc. issecured, said sleeve running through the disc aperture and extendingbeyond the limits of the. side faces of the wheel, said sleeve beingcircumferentially grooved on each end; a shaft on which the sleeve isrotatably mounted, said shaft extending beyond the ends of the sleeve: acup having spaced side members extending upwardlyfrom' the brim of thecup, said shaft being 5 mounted within the confines of the cup andbetween the side members on a level with the brim, whereby the wheel maybe rotated so that its lower half at any given time is within theconfines of the cup: a knife guide having a small end portion and a rimportion for each side of the Wheel, each guide having a central apertureby" which it" may be slipped on the sleeve so the small end portionenters slightly into the aperture in the wheel, said mounting on thesleeve being loose so the guide can wobble slightly thereon inadditionto rotating thereon, each guide having a circle of holes concentric withtheaxis of rotation of the wheel at a radial distancefrom the axis ofrotation of the Wheel so that they are opposite the associatedperipheral edge of the aperture in the wheel for aiding in removingcutting debris, and each of said guides having on the outer surface acircular recessed band between said circle of holes and the outer rim,said band being recessed toward the interior of the cone-to providespaced-apart knifesupporting points: ahelical-spiral spring for eachguide member, the small end of a spring being mounted inthe groove inthe sleeve on the end thereof associated with the associated guidememberand the large, end of the spring abutting the. interior of theassociated guide member to hold it against the wheel; and a fluid heldin the, cup to a level approximating the bottom of the shaft.

7.. Ina knife sharpener, in combination, a fluid holding cup havingupwardly projecting spaced idememb rs; a shaft mounted between the, sidem mbers acrossv the cup atbrimlevel; asleeve r0.- tatablymountedontheshaft, said sleeve. having a, circumferential. groov on. eachend; adisc. mounted on the. sleeve at. its. midpoint, said disc. having aperipheral groove; an abrasivewheel mountedonthe disc,.said disc being;within.a.cen.- tral aperture,- in the; wheel, saidwheelbeing widerv thanthe disc, and: said central aperture of the wheel; having, on the.mid-line of its. periphery a V.-- shaped-groove;, a wire key memberlocking'the, disc and the wheel together in cooperation with the discgroove and V-shaped wheel groove, whereby the wheel isrotatable withinthe cup, the lower half thereof,.at any position of the wheel, beingbelow brim level; a modified truncated hollow conical guide for eachside of the wheel, the hole in the truncated end of a guide allowing itto be mounted on the sleeve, truncated end first, so the truncated endfits slightly into the wheel aperture on the associated side of thewheel, the outer surface of the guide from the truncated end extendingoutwardly and beyond the inner peripheral edge of the Wheel aperture; ahelical-spiral spring for each guide, the small end engaging the groovein the associated sleeve end and the large end engaging the interior ofthe associated cone-guide to hold it against the wheel at the peripheryof the wheel aper ture; 'and a fluid held within the cup to a levelabove the lowest level of holes in the guides.

8. In a knife sharpener, in combination, a fluid holding cup havingupwardly projecting spaced side members; a shaft mounted between theside members across the cup at brim level; a sleeve rotatably mounted onthe shaft, said sleeve having a circumferential groove on each end; adisc mounted on the sleeve at its mid-point; an abrasive wheel mountedon the disc, said disc being within a central aperture in the wheelwhich is wider than the disc, whereby the wheel is rotatable within thecup, the lower half thereof, at any position of the wheel, being belowbrim level; a modified truncated hollow conical guide for each side ofthe wheel, the hole in the truncated end of a guide allowing it to bemounted on the sleeve, truncated end first, so the truncated end fitsslightly into the wheel aperture on the associated side of the wheel,the outer surface of the guide from the truncated end extendingoutwardly and beyond the inner peripheral edge of the'wheel aperture, ahelical-spiral spring for each guide, the small end engaging the groovein the associated sleeve end and the large end engaging the interior ofthe associated cone guide to hold it against the wheel at the peripheryof the wheel aperture; and a fluid held within the cup to a level abovethe lower holes in theguides.

9. In a knife sharpener, in combination, a fluidholding cup having twoupwardly projecting spaced side members; a shaft mounted between theside members across the cup at brim level; a sleeve rotatably mounted onthe shaft, said sleeve having a circumferential groove on each end; adisc mounted on the sleeve at its midpoint; an abrasive wheel mounted onthe disc, said disc being within the central aperture in the wheel whichis wider than the disc, whereby the wheel is rotatable within the cup,the lower half thereof, at anyposition of the wheel, being below brimlevel; .a modified truncated hollow conical guide for each side of thewheel, the hole in the truncated. end of each guide allowing it bemounted on the sleeve, truncated end first, so the truncated end fitsslightly into the wheel aperture on the associated side of the wheel,the outer surface of each of the guides from the truncated end extendingfor a distance outwardly and beyond the inner peripheral edge of thewheel aperture, a helical-spiral spring for each guide, the small endengaging the groove in the associated sleeve end and the large endengaging the interior of the associated guide to hold it against thewheel at the periphery of the wheel aperture.

10. In a knife sharpener, in combination, a fluid holding cup havingupwardly projecting spaced side members; a shaft mounted between theside members across the cup at approximately brim level; a sleeverotatably mounted on the shaft, said sleeve having a circumferentialgroove on each end; a disc mounted on the midpoint of the sleeve; anabrasive wheel'mounted on the disc, said disc being within a centralaperture in the wheel which is wider than the disc, whereby the wheel isrotatable within the cup, the lower half thereof, at any position of thewheel, being below brim level; a modified truncated hollow conical'knife guide for each side of the wheel, the hole in the truncated end ofeach guide allowing it to be mounted on the sleeve, truncated end first,so the truncated end fits slightly into the wheel aperture on theassociated sid of the wheel, the outer surface of the guidefrom thetruncated end extending outwardly and beyond the inner peripheral edgeof the wheel aperture, and each of said guides having a circle of holesconcentric with the axis of rotation of the sleeve and wheel and at aradial distance therefrom to bring the center of said holes even withthe peripheral edge of the aperture in the wheel; a helical-spiralspring for each guide, the small end engaging the groove in theassociated sleeve end and the large end engaging the interior of theassociated cone guide to hold it against the wheel at the periphery ofthe wheel aperture; and a fluid held within the cup to a level above thelowermost holes in the guides.

11. In a knife sharpener, in combination, a fluid holding cup havingupwardly projecting spaced side members; a shaft mounted between theside members across the cup at brim level; an abrasive wheel mounted forrotation on the shaft, within the confines of the cup, the lower half ofthe wheel, at any position of the wheel being below brim level, and saidwheel having a central recess, on each face, of circular contour; amodified truncated hollow'conical guide for each side of the wheel, thehole in the truncated end of each guide allowing it to be mounted,truncated end first,

into the recess on the associated side of the REFERENCES CITED Thefollowing references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 719,880 Rose Feb. 3, 1903 730,706Rose June 9, 1 903 1,398,741 Rose Nov. 29, 1921 1,946,968 Gallagher Feb.13, 1934 2,232,402

Norton Feb. 18, 1941

